Electron discharge device having a radiator integrated therewith



June 20, 1950 H. J. DAILEY I ELECTRON DISCHARGE DEVICE HAVING A RADIATOR INTEGRATED THEREWITH 2 Sheets-Sheet 1 Filed Dec. 15, 1948 June 20., 1950 H. J. DAILEY 7 2,512,143

ELECTRON DISCHARGE DEVICE HAVING A RADIATOR INTEGRATED THEREWI'I'H '2 Sheets-Sheet 2 Filed Dec. 15, 1948 (00. 0/2 area? 4 Aral/M6- dearer/01v w m/ H 2mm mm m v Q Patented June 20, 1950 Y ELECTRON DISCHARGE DEVICE HAVING A RADIATOR INTEGRATED THEREWITH Hampton Jennings Dailey, Verona, N. J assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application December 15, 1948, Serial No..65,434

This invention relates to radiators and more particularly to radiators for electron discharge devices.

Present day transmitting tubes included in the general classification of electron discharge ,devices, are the source of intense heat during operation, and require radiators of good thermal conductivity and adequate surface area to disperse thegenerated 'heat. Radiators employing coppe' fins have been commonly used. While the tubes alone are relatively light, not usually 9 Claims. (01. 250 -275) "a" completebondbetween the liner and the radiawhich like .numerals of reference indicate simiexceeding twenty-five pounds, the copper radiators may be several hundred pounds, and thus require a crew of several men or a crane to handle and to make tube .replacements as needed from time to time. If it were possible to merely substitute aluminum or other light-weight metal or alloy for the copper in fabrication of the radiators, great saving of weight would be accomplished as density of aluminum is approximately 168 pounds per cubic foot as compared with 555 pounds for copper. However, until now, the fabrication of a radiator of aluminum, magnesium or alloy thereof and assembly with a transmitting tube has not proved practical. A prerequisite for a successful radiator is that it must have a secure bond with the copper anode of the transmitting tube, but aluminum, for example, when fabricated, quickly forms a very stable oxide surface to which it is, for all practical purposes, impossible to make a good solder joint. This lack of adequate bond with the anode has prevented adoption of aluminum radiators for transmitting tubes, and similarly has prevented adoption of radiators of other light-Weight metals and alloys.

Accordingly, the fundamental purpose of the present invention, is to provide a practical radiator of light-weight material such as aluminum for an electron discharge device and particularly for a transmitting tube in that classification.

Also, in general terms, an object of the invention is to provide an improved radiator of lightweight material such as aluminum adaptable to attachment to a copper anode of an electron discharge device with a secure bond therewith.

More specifically, an object of the invention is to include within the radiator a means by which secure attachment between radiator and anode may be obtained.

Another object of the invention is to provide a liner for the radiator which can be soldered to the anode.

Yet another object of the invention'is to obtain tor hub or body. v

A further object of the invention is to provide an improved method of fabrication.

Still other objects of the invention will appear to those skilled in theart to which it appertains as the description procee da both by direct recitationthereof and by implicaion from the context.

Referring to the accompanying drawings in lar parts throughout the several views:

Fig. l is' a longitudinal section of a'radiator fabricated in accordance with the present invention and "shown applied to an anode, which is depicted partly in section and partly in elevation;

Fig. 2 is a transverse section on line IIII of Fig, 1; and

Figs. 3 to 8 are longitudinal sectional views showing successive steps in fabrication of the improved radiator of the present invention.

In the specific embodiment of the invention illustrated in said drawings, the reference numeral 'Ill designates an electron discharge device in generaL'having usual triode or other electrodes of which the anode ll shown herein is formed as part of the envelope with which it is appropriately sealed so as to be evacuated, the

5 lower end of said anode being closed as by an integrally formed dome l2. The anode is usually made of copper and in the construction shown is an exterior part of the tube so as to be available for'heat dissipation.

The radiator, designated in general by nuneral [3, comprises a hollow body or hub M from which, in radial planes, project a plurality of fins [5. The present invention contemplates use of light-weight metal such as aluminum, magnesium, or alloys thereof, as the material of which said hub l4 and fins [5 are fabricated. As indidated in Fig. 7, the exterior cylindrical surface of the hub is milled with a, plurality of longitudinal'grooves I6, onefor each fin, and the inner edges of the fins are applied in the grooves and brazed or otherwise securely attached throughout their engaging portions with the hub.

The interior of the radiator body or hub is provided with means for enabling the body to be securely attachedto the anode throughout the juxtaposed surfaces after telescoping the said body upon the anode. According to the present invention, a metallic liner I1 is made integral with the said hub and constitutes the inner surface'of the radiator body. Said liner is integrated with'the hub so, as to transmit heat by conducminum or other metal of the body in the aforementioned molding operation.

After the molding operation and cooling are efiected, the hub is trimmed to length and the exterior surface is milled, as indicated in Fig. 7, to provide the series of parallel grooves IB longitudinally' of the hub for reception and retention of fins [5. Plug i8 is inserted in the end of the body and then the plug and fins are simulvenience and accuracy of assembly; thelower end 7;

diameter of the central hollow or cavity'through the hub is greater than the diameter of the liner cavity so as to provide a shoulder 19 against which the plu 01- cap will sea'ta't its peripheral margin.

In carrying out the method of rabricanon; theliner is first given a temporary coating 21) on its interior or hollow surface as indicated in Fig. 3, of a material resistive to adhesion of aluminum or other metal of which the hub is to be cast, and protective against chemical reaction either with said metal or aluminum, or with oxygen, or the F metal of the said ferrous groupof which theliner is composed. Such a coating material may appropriately be graphite or similar carbonaceous compound of which Aquadag is one well suited to the purpose. The liner is then submerged in molten aluminum 2| or equivalent metal, shown in Fig. 3 as kept in its fluid state by inclusion in an electrically heated pot 22.. By virtue of the temporary protective coating on the inside of' the liner, no reaction takes place between the molten metal or aluminum and the innersurface oi the liner, but in view of the direct contact of the outer surface of the'liner with the molten aluminum, a coating of aluminide 23 is formed thereon. With an iron or steel liner, the aluminide coating 23 will be iron aluminide, whereas with a nickel liner, the coating thus chemically formed will be nickel aluminide. The liner is then withdrawn from the molten-aluminum, shown as accomplished in Fig. e, and mounted upon a slug 24 substantially filling the cavity of the liner and protruding at the-ends to constitute a male molding core. The liner, with its included molding core or slug'24 is then in- 1 serted in a female mold 25 of cylindrical shape and coaxially thereof, after which molten lightweight metal such as aluminum 2B is poured into the mold to form in this specific instance the aluminum hub or body I4 upon the liner, shown accomplished in Fig. 5. This aluminum 26 will" bond with the liner on the surface thereof hav- V ing the aluminide coating 23, and thus iorms the hub or body M which becomes an integral part with the liner. The integrationof hub and liner is made more positive and permanent by cooling f the hub first at the outside and progressively gin-j wardly toward the liner. As indicated in Fig. 6, slug 24 is therefore preferably hot, and as con-j ditions may warrant, can be the original slug used as the above-described male molding core,

or may be a substituted and especially heated' slug applied immediately upon withdrawalof the hub or body from its female-'mold 25." 'Then' cool air or other cooling medium is appliedto the exterior of the light-weight metal or aluQ- minum hub or body, as indicated by arrows 21, obtaining the desired cooling thereof progres sively from the outside inwardly.

For further enhancing permanent integration;

of the body or hub upon the liner, the'endsoi the liner are preferably flared outward ya'sat 28, and are therefore fully embeddedin the am-7'5 'taneously brazed in place.

-; At a convenient stage in the procedure subse- '.quent to molding and cooling the body, the graphite or other temporary protective coating 20 on the interior of the liner is removed mechanically 6.6 ic 11y, and when the assembled radiator is then introduced into the hollow of the radiator and heat applied until the solder is liquefied and the anode is then pressed into the hollow of the radiator until solder extrudes at the top of the radiator cavityand the parts have desired relation. The solder 29 will harden and tenaciously adhere to theliner and to the anode and provides an excellent heat-conductive path from the anode tothe radiator. The solder performs the function of providing a secure bond which will not deteriorate by oxidation. By providing a structure enabling the radiator to be fabricated from aluminum or equivalent metal, a relatively light-weight radiator is obtained, and as comparative weights, it may be pointed out that where a prior artcopper radiator weighed 225 pounds,

'an equivalent aluminum radiator in accordance with the present invention weighs only 98 pounds, thereby enabling one man to make a tube replacement in service. Since handling can be done by one man, the apparatus may be more compactly arranged, thus saving space in the transmitter station. Furthermore, providing lighter weight radiators of the present invention reduces shipping costs considerably.

v I claim:

anode and radiator-interposed between the anode and radiatorand secured to both.

2. An electron discharge device comprising a copper anode, an aluminum radiator mounted on said anodefand a liner of metal of the ferrous group interposed between the anode and radiator and secured to both.

3 An electron discharge device comprising a copper anode, an aluminum radiator mounted on saidanoda and a ferrous liner interposed be- .tween the anode and radiator and s cured to both;

4. An electron discharge device comprising a copper anode, an aluminum radiator mounted on said' anoddwand'a nickel liner interposed between ,the'anode and radiator and secured to both.

5. Anelectron discharge device comprising a copper anode, an aluminum radiator mounted on said anode, a liner of a metal different from the anode and radiator interposed between the anode and radiator, said liner having a coating of an aluminide of said metal thereof interposed bei tween the liner and radiator for integrating said liner and radiator as a unit, and solder interposed'between said anode and liner for securing the said lineron the anode.

6. 'A hollow radiator foran electron discharge device comprising an aluminum hub, fins projecting from said hub, a liner of metal of the ferrous group within said hub and providing an inner surf-ace for th hollow of the radiator to which solder will adhere, and a coating of an aluminide of the said metal of the liner interposed between and adherent to both the liner and the hub for inseparably integrating the liner and hub as a unit.

7. A hollow radiator for an electron discharge device, comprising an aluminum hub, fins projecting from said hub, a liner of ferrous metal within said hub and providing an inner surface for the hollow of the radiator to which solder will adhere, and a coating of ferrous aluminide interposed between and adherent to both the liner and the hub for inseparably integrating the liner and hub as a unit.

8. A hollow radiator for an electron discharge device, comprising an aluminum hub, fins projecting from said hub, a nickel liner within said hub and providing an inner surface for the hollow of the radiator to which solder will adhere, and a coating of nickel aluminide interposed between 6 and adherent to both the liner and the .hub for inseparably integrating the liner and hub as a unit.

9. A hollow radiator for an electron discharge device, comprising a hub, fins projecting from said hub, and a liner within said hub providing an inner surface for thehollow of the radiator, said liner having a length less than the length of the hub and having flared ends embedded in the said hub.

HAMPTON JENNINGS DAILEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,924,368 McCullough Aug. 29, 1933 2,107,943 Hopkins Feb. 8, 1938 2,147,407 Huston et al Feb. 14, 1939 2,288,380 Wing, Jr. June 30, 1942 2,447,719 Sorg Aug. 24, 1948 

